A novel self-aligned SiGe HBT structure using selective and non-selective epitaxy

A novel self-aligned SiGe HBT structure using selective and nos-selective epitaxy is proposed. It is shown that damage in the silicon substrate induced by reactive ion etching can be effectively removed and that this allows the growth of high quality selective and non-selective epitaxy. It is also shown in that selective epitaxy followed by non-selective epitaxy can be performed in one process step while controlling the base thickness and doping