MANUFACTURE OF SUPERSELF-ALIGNED VERTICAL BIPOLAR TRANSISTOR

PURPOSE: To realize up/down motion mode by isolating an active region through the use of a simple photolithography and eliminating the trench isolation step which causes lowering of the extent of integration and deterioration of the element thereby obtaining a super self-aligned vertical structure of emitter, base and collector regions. CONSTITUTION: Trench isolation step is eliminated by isolating an active region through the use of simple photolithography thus simplifying the process and improving the extent of integration. Since the emitter, base and collector regions 34, 32, 31 have self-aligned vertical structure, an up/down motion mode can be realized. Size of the element and the parasitic capacitance between a subcollector and board can be reduced by removing the unnecessary region of an isolation film and an insulation defining the active region. Furthermore, an ultrathin film base and an interconnect polysilicon layer are grown entirely in a SEG, thickness of the insulation layer is limited and since thin films 23, 24, 25, 26 are utilized, parasitic capacitance between metal interconnections is reduced.