CHANNEL REPLACEMENT AND BIMODAL DOPING SCHEME FOR BULK FINFET THRESHOLD VOLTAGE MODULATION WITH REDUCED PERFORMANCE PENALTY

摘要

A method includes removing a top portion of a substrate after implantation of a punch through stopper into the substrate; epitaxially growing undoped material on the substrate, thereby forming a channel; filling a top portion of the channel with an intermediate implant forming a vertically bi-modal dopant distribution, with one doping concentration peak in the top portion of the channel and another doping concentration peak in the punch through stopper; and patterning fins into the channel and the punch though stopper to form a finFET structure.