Patent ID: 6900519
Filing Date: 2005-05-31
Classification: H01L

Abstract:
1. A transistor comprising: an epitaxial layer on a semiconductor substrate; a dopant source dopant source layer on the epitaxial layer; and dopant from the dopant source layer distributed within the epitaxial layer to form at least a portion of an extrinsic base for the transistor within the epitaxial layer, a first surface of said portion of the extrinsic base being in direct mechanical contact with the dopant source layer, said portion of the extrinsic base being disposed between the dopant source layer and an intrinsic base for the transistor, said intrinsic base being totally within the epitaxial layer, a second surface of said portion of the extrinsic base being in direct mechanical contact with the intrinsic base, said second surface being opposite said first surface and not contacting said first surface.