Abstract: A tube furnace used for high-temperature processing of semiconductor wafers or the like employs features to improve the gas flow. One feature is reducing, or essentially eliminating, regions of gas recirculation in the outer annular region inherently present in a horizontal hot-wall atmospheric oxidation reactor equipped with a tubular cantilever for holding semiconductor wafers. The annular region is effectively isolated from the rest of the reactor by a solid circular quartz ring or barrier formed on the inner wall of the furnace tube, acting as a physical barrier against gas penetration inside the outer annulus.

Abstract: A tube furnace used for high-temperature processing of semiconductor wafers or the like employs features to improve the gas flow. A primary feature of this invention is improving the plug flow characteristics of the furnace by preventing the undesirable elongation of the gas jet entering the reaction system through the injector nozzle. This elongated gas jet induces unwanted turbulence within the system and causes premature and incomplete mixing of reactant gases in the longitudinal direction. Improvement in plug flow characteristics is attained by use of a quartz baffle at the entrance region of the reactor located a distance from the gas inlet. The shape and location of the baffle are such that it acts as a physical barrier against the elongated gas jet and confines the turbulence in the initial fill chamber created by the entrance region of the reactor and the baffle.