Selective epitaxy base transistor (SEBT)

Abstract

A bipolar transistor using selective epitaxy for base formation in a double-poly self-aligned structure is presented. The intrinsic base was formed by a selective-epitaxial deposition in place of ion implantation. Such epitaxial base processes are capable of achieving a narrow intrinsic base sheet resistance R/sub bi/ and base-emitter diffusion capacitance c/sub be/ compared to advanced ion-implanted processes. A selective epitaxial base can be simply introduced in advanced double-poly self-aligned processes compared to a nonselective epitaxial layer.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>