Silicon-germanium heterojunction bipolar transistor

摘要

A SiGe HBT is disclosed. A collector region consists of a first ion implantation region in an active area as well as second and third ion implantation regions respectively at bottom of field oxide regions. Each third ion implantation region has a width smaller than that of the field oxide region, has one side connected to first ion implantation region and has second side connected to a pseudo buried layer; each second ion implantation region located at bottom of the third ion implantation region and pseudo buried layer is connected to them and has a width equal to that of the field oxide region. Third ion implantation region has a higher doping concentration and a smaller junction depth than those of first and second ion implantation regions. Deep hole contacts are formed on top of pseudo buried layers in field oxide regions to pick up collector region.