公开(公告)号：BR8903449A

公开(公告)日：1990-03-06

申请号：BR8903449

申请日：1989-07-13

Applicant: IBM

Inventor： BURGHARTZ JOACHIM NORBERT ,  GINSBERG BARRY JACK ,  MADER SIEGFRIED R

IPC: H01L29/73 ,  H01L21/331 ,  H01L29/732 ,  H01L21/20 ,  H01L21/306 ,  H01L29/70

Abstract: Bipolar transistors having self-aligned emitter-base regions and a method of forming such transistors using selective and non-selective epitaxy are disclosed. A substrate (12) of semiconductor material of a first conductivity type, a portion of which forms a collector region is provided. A first layer (18) of semiconductor material of a second conductivity type is deposited on said substrate, a portion of which forms an intrinsic base region. Over a portion of said first layer (18) an element (30) of insulating material is formed. Said intrinsic base region is formed below said element (30) and the remainder of said first layer forms an extrinsic base region. A second layer (32) of semiconductor material of said second conductivity type is deposited on said first layer (18). A portion of said second layer laterally overgrows onto a portion of an upper surface (33) of said element (30) defining an aperture (29) and leaving an exposed region (31) on the upper surface (33). The second layer (32) forms a portion of the extrinsic base region. On said second layer (32) a layer (42) of insulating material is formed which narrows said aperture (29) and said exposed region (31) of said element (30). Said narrowed exposed region (31) of said element (30) is removed to expose a portion (50) of said first layer (21) below said aperture (29) and an emitter region (54) of said first conductivity type is formed in said first layer (21) through said aperture (44).