Cooling system and method for epitaxial barrel reactor

A method for operating a barrel reactor to inhibit metals contamination in semiconductor wafers processed in the barrel reactor caused by chemical reactions with metallic surfaces of the barrel reactor, the method comprising the steps of:

• opening the barrel reactor to place semiconductor wafers on which material is to be deposited by chemical vapor deposition into a reaction chamber of the barrel reactor;
• sealing the reaction chamber;
• activating the barrel reactor to deliver gas including the material to be deposited on the wafers into the reaction chamber;
• transferring heat, when the barrel reactor is activated, between the metallic surfaces of the barrel reactor which are exposed to the reaction chamber when the reaction chamber is sealed and a coolant fluid;
• controlling the heat transferred to maintain the metallic surfaces at a first temperature selected to retard chemical reactions on the metallic surfaces while the barrel reactor is activated;
• de-activating the barrel reactor;
• opening the barrel reactor to expose wafers in the reaction chamber thereof for removal from the barrel reactor;
• transferring heat when the barrel reactor is de-activated, between the metallic surfaces of the barrel reactor which are exposed to the reaction chamber when the reaction chamber is sealed and the coolant fluid;
• controlling the heat transferred to maintain the metallic surfaces at a second temperature greater than the first temperature when transferring heat while the barrel reactor is de-activated, the second temperature being selected to retard adsorption of water on the metallic surfaces while the barrel reactor is de-activated.

A barrel reactor constructed to inhibit metals contamination in semiconductor wafers processed in the barrel reactor caused by chemical reactions with metallic surfaces of the barrel reactor, the barrel reactor comprising:

• means for opening the barrel reactor to place semiconductor wafers on which material is to be deposited by chemical vapor deposition into a reaction chamber of the barrel reactor;
• means for sealing the reaction chamber;
• means for activating the barrel reactor to deliver gas including the material to be deposited on the wafers into the reaction chamber;
• means for transferring heat, when the barrel reactor is activated, between the metallic surfaces of the barrel reactor which are exposed to the reaction chamber when the reaction chamber is sealed and a coolant fluid;
• means for controlling the heat transferred to maintain the metallic surfaces at a first temperature selected to retard chemical reactions on the metallic surfaces while the barrel reactor is activated;
• said activating means being capable of de-activating the barrel reactor;
• said opening means being capable of opening the barrel reactor to expose wafers in the reaction chamber thereof for removal from the barrel reactor;
• said heat transferring means being capable, when the barrel reactor is de-activated, of transferring heat between the metallic surfaces of the barrel reactor which are exposed to the reaction chamber when the reaction chamber is sealed and the coolant fluid;
• said controlling means being configured to control the heat transferred when the barrel reactor is de-activated to maintain the metallic surfaces at a second temperature greater than the first temperature, the second temperature being selected to retard adsorption of water by the metallic surfaces while the barrel reactor is de-activated.