Modular V-CVD diffusion furnace

Claim 1

A modular vacuum chemical vapor deposition CVD diffusion furnace, comprising: a cylindrical diffusion tube having open ends and defining a cylindrical reaction chamber having an operative region along which CVD takes place; a boat loader; means for removably fastening said boat loader in air-tight sealing engagement with one of said open ends; means coupled to said diffusion tube for controllably heating said reaction chamber; a vacuum source; a first metallic door having an aperture and a plurality of precisely aligned gas injection tube receiving openings provided through the door spaced from each other and from said aperture; means for connecting said vacuum source to said aperture; a plurality of gas injection tubes slidably received in a corresponding one of said plurality of precisely aligned gas injection tube receiving openings and each having an end terminating at longitudinally spaced points along said operative region of and within said reaction chamber; a like plurality of vacuum couplings intermediate each of said gas injection tube receiving openings and a corresponding one of said gas injection tubes; a gas control system operatively connected to said plurality of gas injection tubes; and means for removably fastening said first metallic door to the other one of said ends of said cylindrical diffusion tube in air-tight sealing relationship.