Chemical vapor deposition of epitaxial silicon

A method for silicon epitaxial growth by continuous chemical vapor deposition of silicon material deposited continuously epitaxially on a flat substrate surface of crystalline material in a reactor tube defined by an elongated open chamber having a longitudinal axis and having respective ends connected to a gas input section and a gas output section, comprising the steps of:

• providing at said input section a longitudinal substantially laminar flow of a first stream of a chemical source gas containing said material and a carrier gas through a first longitudinal passageway having a predetermined distance in a first zone of said chamber;
• providing at said input section a longitudinal substantially laminar flow of a second gas stream through said chamber along a path in a second longitudinal passageway having the same said predetermined distance and isolated from but substantially parallel to said first passageway carrying said first gas stream through said first longitudinal zone of said chamber;
• moving substrates at a rate of about 0.5 feet/minute serially and longitudinally through said chamber adjacent only to said second gas stream in said isolated passageway and in a path substantially parallel to said first and second passageways;
• diffusing in a second longitudinal zone of said chamber said first gas stream into said second stream at the end of said first zone to effect epitaxial deposition of the silicon material from said first stream on the surface of said substrates such that the epitaxial deposition rate resulting from said diffusion at the entrance and exit portions of said second zone is less than the epitaxial deposition rate in the intermediate portion of the second zone;
• heating to a predetermined temperature said substrates before passing into said second zone;
• balancing the forward momentums of the first and second gas streams to be substantially equal and to thereby reduce turbulent flow of the gas streams towards a minimum as they diffuse together subsequent to passing through their said respective passageways for said predetermined distance;
• and
• passing said substrates through a third passageway in a third longitudinal zone while passing a stream of purging gas through said third passageway, said second gas stream and said purging gas stream serving to provide a viscous seal at the input section and output section of said chamber;
• the first, second and third longitudinal zones extending along chamber axis whereby the substrates and gases are moved longitudinally substantially linearly along said longitudinal axis through said chamber;
• whereby a significantly large throughput of substrates deposited with said material to a substantially uniform thickness can be achieved at a high rate as the turbulence of said respective gas streams is reduced to a minimum.