SELF-ALIGNED STRUCTURE FOR BULK FinFET

摘要

A FinFET structure which includes a bulk semiconductor substrate; semiconductor fins extending from the bulk semiconductor substrate, each of the semiconductor fins having a top portion and a bottom portion such that the bottom portion of the semiconductor fins is doped and the top portion of the semiconductor fins is undoped; a portion of the bulk semiconductor substrate directly underneath the plurality of semiconductor fins being doped to form an n+ or p+ well; and an oxide formed between the bottom portions of the fins. Also disclosed is a method for forming a FinFET device.

主权项

1. A method of forming a FinFET device comprising, in the following order:
forming a plurality of semiconductor fins from a bulk semiconductor substrate; forming an oxide layer between each of the plurality of semiconductor fins, the oxide layer extending from the bulk semiconductor substrate only part way up a sidewall of each of the semiconductor fins to cover a bottom portion of each of the semiconductor fins, a top portion of the sidewall of each of the semiconductor fins being exposed and not covered by the oxide layer; forming a dummy spacer on the exposed top portion of each of the semiconductor fins; completely stripping the oxide layer to expose the bulk semiconductor substrate and the bottom portion of each of the semiconductor fins; depositing a doping material to be in contact with the exposed bulk semiconductor substrate and the bottom portion of each of the semiconductor fins previously covered by the oxide layer; heat treating the bulk semiconductor substrate to drive in dopants from the doping material into the exposed bulk semiconductor substrate and the bottom portion of each of the semiconductor fins; stripping the doping material; forming a second oxide layer only in contact with the exposed bulk semiconductor substrate and the bottom portion of each of the semiconductor fins previously contacted by the doping material; and stripping the dummy spacer from each of the semiconductor fins.