Patent ID: 7122085

Claim:
A sublimation apparatus for producing a vapor reactant for flowing through a reaction chamber, comprising: a sublimation vessel; a plurality of beds of solid source for the vapor reactant, each solid source bed contained within the vessel and in the form of a solid powder; a carrier gas guidance structure with which the solid source is directly in contact, the carrier gas guidance structure configured to guide a carrier gas to contact the solid source for the vapor reactant by providing a substantially helical pathway for the carrier gas, wherein the carrier gas guidance structure comprises: a plurality of stacked trays, each tray containing one of the beds of the solid source and confining the carrier gas to a single path from a tray inlet to a tray outlet, the single path defining one of a plurality of levels of the helical pathway, the carrier gas being in contact along the single path with the solid source in each tray; a vessel inlet port located at the beginning of the substantially helical pathway provided by the carrier gas guidance structure; and a vessel outlet port located at the end of the substantially helical pathway provided by the carrier gas guidance structure, wherein the carrier gas guidance structure is configured to ensure contact of the carrier gas with the solid source for the vapor reactant along the substantially helical pathway having a length greater than about 2.5 times a linear distance measured from the vessel inlet port to the vessel outlet port.