Method for manufacturing lateral bipolar transistors

Method for manufacturing a lateral bipolar transistor, comprising the steps of:

• laterally electrically insulating a region for forming a transistor in a silicon layer located on an insulation layer, said region having a basic doping;
• manufacturing a highly doped base terminal zone and a highly doped collector zone by implantation of dopants in said silicon layer using masks;
• applying a structured dielectric layer having a selected thickness over said silicon layer to cover said base terminal zone and to cover a region for forming a collector, leaving free a region for a base zone and for an emitter zone, said structured layer having a vertical sidewall relative to a layer plane at a boundary between said covered region and said region left free, said structured layer having a selected thickness;
• implanting a dopant in said base zone in said silicon layer having a first conductivity type using said dielectric layer as mask;
• isotropically applying an auxiliary layer surface-wide over said structured dielectric layer with a thickness measured in the direction of emitter to collector that corresponds to the length for said base zone;
• implanting a dopant in said emitter zone in said silicon layer having a second conductivity type to form a highly doped emitter zone using said auxiliary layer as shielding for said base zone;
• producing via holes through said auxiliary layer and said dielectric layer respectively exposing said emitter zone, said base terminal zone, and said collector zone;
• and
• applying metal electrical contacts in said via holes to said emitter zone, base terminal zone and collector zone.