Patent ID: 6680234
Filing Date: 2004-01-20
Classification: H01L,Y10S

Abstract:
A method for manufacturing a semiconductor with a SiGe base bipolar transistor, comprising:providing a P-type silicon substrate; forming an N-type buried layer having a high concentration in said P-type silicon substrate forming a collector layer comprised of an N-type layer having a low concentration on said N-type buried layer; forming a SiGe base layer on said collector layer, wherein forming said SiGe base layer comprises: forming an undoped SiGe layer on said N-type collector layer; forming a first SiGe base layer having a first Ge concentration distribution on said undoped SiGe layer; and forming a second SiGe base having a second Ge concentration distribution on said first SiGe base layer; and forming an emitter layer comprised of an N-type diffusion layer in said second SiGe base layer, wherein a Ge concentration of said SiGe base layer is increased from 0% to 10% from a side of said emitter layer towards a side of said collector layer.