Patent ID: 6296709
Filing Date: 2001-10-02
Classification: H01L,Y10S

Abstract:
A vertical diffusion furnace for semiconductor manufacturing processes comprising:a vertical processing tube for housing a plurality of semiconductor wafers; said processing tube having a tube wall capable of being heated to a predetermined temperature;a first gas conduit, connected to said processing tube and a source of process gas, said source being capable of supplying the process gas to said processing tube;a second gas conduit, connected to said processing tube and a source of preheated process gas, said source being capable of supplying the preheated process gas to said processing tube; andcontrol unit for said first and said gas conduits, said control unit configured so as to cause said process gas to be supplied to said process tube through said first conduit at approximately room temperature during ramp-up and said preheated process gas to be supplied to said processing tube through said second gas conduit at said predetermined temperature of said tube during ramp down.