Patent ID: 8133322

Claim:
A semiconductor fabrication reactor, comprising: a rotatable susceptor mounted to a top surface of a reactor chamber, said reactor chamber having a bottom surface opposite said top surface, said susceptor having a face down surface that faces toward said bottom surface; first and second sidewalls arranged between said top surface and said bottom surface, said susceptor arranged between said sidewalls and arranged between said top surface and said bottom surface; a plurality of wafers mounted to said susceptor's face down surface, the rotation of said susceptor causing said wafers to rotate within said chamber; a heater remote to said susceptor and arranged to heat said susceptor; one or more chamber gas inlets, each of which allows semiconductor growth gasses into said reactor chamber to deposit semiconductor material on said wafers, each of said inlets below said face down surface; a chamber gas outlet through said top surface arranged to allow gases to exit from the interior of said reactor chamber, said gas outlet arranged to open to said reactor chamber interior such that gases enter said gas outlet at a location entirely above said susceptor; wherein said chamber gas outlet is coupled to said top surface and said chamber gas outlet is arranged entirely above said sidewalls; wherein said top surface is arranged entirely above said susceptor; and wherein said inlet and outlet are arranged to produce a gas flow up from said one or more inlets, over said wafers, and out said outlet so that growth gasses that do not deposit on said wafers are drawn above said face down surface, such that growth gas impurities are primarily deposited on the surfaces of said reactor chamber above said face down surface.