Patent ID: 7632354

Claim:
A thermal processing system for processing substrates with a process gas, the thermal processing system comprising: an outer tube; an inner tube disposed radially inside said outer tube, said inner tube defining a processing space in which the substrates are held for processing with the process gas; and a gas injector having an injection section positioned inside said inner tube and a delivery section, said injection section having a first end, a second end that is closed and opposite to said first end, a baffle attached to said first end and extending from said first end of said injection section toward said second end of said injection section, a first fluid lumen between said first end of said injection section and said second end of said injection section, a second fluid lumen separated from said first fluid lumen by said baffle and extending from said first end of said injection section to said second end of said injection section, a first inlet in said first end that couples said first fluid lumen with said delivery section for communicating the process gas to said first fluid lumen, and a plurality of injection outlets distributed along said second fluid lumen between said first and second ends of said injection section, said injection outlets configured to inject the process gas from said second fluid lumen into said processing space, said first fluid lumen free from said injection outlets, and said first fluid lumen intersecting said second fluid lumen at a second inlet between said first and second ends of said injection section, whereby said first fluid lumen communicates the process gas through said second inlet to said second fluid lumen of said injection section, wherein said injection section has a length measured between said first and second ends and along which said injection outlets are distributed, and said baffle has a length that is equal to a product between a multiplicative factor ranging from about 0.4 to about 0.5 of said length of said injection section.