Controlled diffusion environment capsule and system

摘要

A controlled diffusion environment capsule system (10) is used with a conventional tubular high temperature furnace (12) as employed in semiconductor manufacturing. The system (10) includes a cantilever boat loading apparatus (14) and a quartz diffusion capsule (16). Wafer carriers (20) support semiconductor wafers (22) concentrically with capsule (16) in closely spaced relationship for processing in the furnace (12). The diffusion capsule (16) is supported on a pair of quartz rods (24). A quartz injector tube (28) extends the length of the diffusion capsule (16). The injector tube (28) has three rows of high aspect-ratio apertures (30) extending along its length to disperse nitrogen or other inert gas uniformly across the sufaces (32) of the wafers (22). A quartz extender (34) is connected to the distal end of the diffusion capsule (16), through which reactant gases are supplied to the capsule (16) for diffusion and/or oxidation, from an inlet source (35) of the reactant gases on the furnace tube near the extender (34). The extender (34) has two apertured baffle plates (36) and (38) which have holes (40) and (42) in patterns that are offset relative to one another. A third plate (44) has a larger hole (46) at its center. The hole (46) focuses reactant gases into the capsule and the holes (40) and (42) provide turbulence to the reactant gas stream prior to its entry into the capsule (16) to assure uniform mixing.